Cold hardiness & minimum temperature

Is Echinocereus coccineus (Echinocereus coccineus)cold hardy? Hardiness zone & min temp

Also called Scarlet Hedgehog Cactus, Red Pitaya.

More about echinocereus coccineus

About Echinocereus coccineus

Echinocereus coccineus · also called Scarlet Hedgehog Cactus, Red Pitaya · flowering

Echinocereus coccineus, the scarlet hedgehog or red pitaya, is a cold-hardy clumping cactus of the US Southwest and northern Mexico. It is loved for its brilliant orange-scarlet, hummingbird-pollinated spring flowers that persist for days. Forming dense mounds of spiny stems, it needs full sun, very sharp drainage and a cold, dry winter to flower well.

Cold limit: USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry) · RHS H4 (5-32°C)

Watch for — No blooms: Usually too warm or too wet in winter, or too little sun. Give a cold, completely dry dormancy and maximum light to set the scarlet flowers.

What echinocereus coccineus's hardiness rating actually means

Yes — echinocereus coccineus is genuinely cold hardy. Rated RHS H4 and USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry), it lives outdoors all year and needs winter cold rather than protection from it. Its RHS rating of H4 means: Hardy in an average winter across much of the temperate world. On the US scale that maps to USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry) — the zones where it can be left outdoors year-round.

New to these scales? The USDA hardiness zone map explained covers how the zone numbers work, and you can find your own zone with the zone finder.

Minimum temperature — and what happens below it

Minimum survivable temperature is roughly about −10 to −5 °C. Echinocereus coccineus is built for winter — once established it takes hard frost and snow in its stride.

Concretely, for echinocereus coccineus as it gets too cold:

It tolerates winter lows to about −10 to −5 °C once established.
Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root.
First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.

Can echinocereus coccineus go outside or overwinter — and where?

Plant it out within USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry) and it overwinters with little or no help.
It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy.
The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

Work back from your local frost dates with the frost-date calculator: the last spring frost and first autumn frost are what really decide when echinocereus coccineus can be outside. US growers can check USDA zones; UK growers should use the RHS hardiness ratings, which match the H4 figure above.

Echinocereus coccineus hardiness — frequently asked questions

Is echinocereus coccineus cold hardy?

Yes — echinocereus coccineus is genuinely cold hardy. Rated RHS H4 and USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry), it lives outdoors all year and needs winter cold rather than protection from it. An outdoor plant. Echinocereus coccineus is hardy across USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry); it belongs in the ground or a frost-proof container, not on a windowsill, and many types actively need a cold winter to perform.

What is the minimum temperature echinocereus coccineus can survive?

Minimum survivable temperature is roughly about −10 to −5 °C. Echinocereus coccineus is built for winter — once established it takes hard frost and snow in its stride.

What hardiness zone is echinocereus coccineus?

Echinocereus coccineus is rated USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry) and RHS H4 — Hardy in an average winter across much of the temperate world.

Can echinocereus coccineus survive winter outside?

Plant it out within USDA 5-10 (one of the more frost-hardy hedgehog cacti when dry) and it overwinters with little or no help. It does not want to come indoors — a warm winter room actually weakens a hardy plant by denying it dormancy. The real risks in its range are waterlogging, wind-rock on young plants, and a late hard frost on new growth — not ordinary winter cold.

What happens to echinocereus coccineus below its minimum temperature?

It tolerates winter lows to about −10 to −5 °C once established. Below its rated zone, the visible damage is browned or blackened top growth and, in the worst case, a killed crown or root. First-year, newly planted, or container-grown specimens are noticeably less hardy than established garden plants — the roots are exposed.